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Production technology of plastic unit base
Vyškovský, Stanislav ; Kebrle, Ondřej (referee) ; Kandus, Bohumil (advisor)
Thermoplastic injection technology is widely used in all sectors of consumer electronics and automotive industry. The biggest advantage of this manufacturing technology is a high degree of automatization and good reproducibility of the manufacturing process. Another advantage is the possibility of recycling of the gating scrap and defective products. The main task of this work is to calculate the necessary parameters for the injection process, which takes place at the designed injection form. Next part is technical design which includes choice of standard parts of injection mold and idividual semi-finished parts for mold. Thesis continues with selecting the type of injection press based on calculated parameters of the injection process. Thesis is finished by technical-economic evaluation.
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Trend development of tools for production sinuses forms
Fišer, Michal ; Sliwková, Petra (referee) ; Osička, Karel (advisor)
This thesis descibes questions of tools for production of shape hollows focused especially on milling and electroerosion machining. Here you can find individual tools included their description and characteristics, toolmakers and their news. Here are mentioned methods and contemporary trend of cutting. Here is comparison of several tools in concrete applications. Included is also list of basic types of milling tools clamping. In conclustion there is mentioned further development of tools and their using.
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Verification of the original technologies used for art castings
Hřebíček, Lukáš ; Mrázek, Martin (referee) ; Horáček, Milan (advisor)
This diploma thesis is describing making of the same art casting by using different foundry technologies/ moulds (ceramic shell mould, several types of plaster moulds including anhydride gypsum and also natural sand mould). In this thesis there is also description of casting the famous piece of bull from “Byci skala” (Bull Rock). The bull was cast into traditional clay mould which is believed to be the original technology. Also the original shape of the bull casting was reconstructed, i.e. a copy of the original bull casting made. As the main achievement of this work is an overview and comparison of several technologies suitable for making art castings.
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Production and characteritzation of extracellular hydrolases from selected moulds
Skoumalová, Petra ; Čarnecká, Martina (referee) ; Márová, Ivana (advisor)
This diploma thesis is focused on study of potential production of extracellular hydrolytic enzymes. The theoretical part deals with characterization of selected hydrolytic enzymes, their catalytic properties, the possibility of extracellular hydrolase production by fungi and their applications. In experimental part production strains Aureobasidium pullulans, Fusarium solani and Phanerochaete chrysosporium were used. Productions of cellulase, amylase, xylanase, lipase, protease and lignin-degraded enzymes (laccase, manganese- dependent peroxidase, lignin peroxidase) were observed. Cultivations were carried out in submersed mode in mineral medium supplemented by waste co-substrates such as wheat bran, corn bran, rice bran and oat bran, sawdust, rice, apple fiber, egg pasta and egg-free pasta. Production of enzymes depended on the substrate type and time of cultivation. The highest cellulase, xylanase and amylase activities were measured in the first period of cultivation (3 to 7 day). Lignin-degraded enzymes and proteases were produced at the end of cultivation (7 to 10 days). Lipolytic activity was detected only in A. pullulans, where the activity increased with time of cultivation. The highest value was determined during cultivation on wheat bran (3.6 nmol/ml.min). The highest xylanase and celulase activity (170.3 nmol/ml.min, 248.0 nmol/ml.min) were determined during cultivation of F. solani on corn bran. The highest amylase activity (111.8 nmol/ml.min) was reported in P. chrysosporium during the cultivation on rice. The highest protease activity (68.0 nmol/ml.min) was determined in F. solani grown on wheat bran. The best producer of laccase was A. pullulans, the highest production was recorded for egg-free pasta (27.0 nmol/ml.min). The maximum lignin peroxidase activity (12.5 nmol/ml.min) was measured during the cultivation of F. solani on egg pasta, while the highest yield of Mn-dependent peroxidase (7.7 nmol/ml.min) was achieved during the cultivation of A. pullulans on wheat bran. Lignin-degraded enzymes behaved as inductive, while the other enzymes were produced in mineral medium too. Activity of cellulase in the mineral medium was in A. pullulans strain higher than in media with waste substrates. Enzymes produced into A. pullulans medium were purified by ultrafiltration, ion exchange chromatography and gel filtration.
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Enzymatic hydrolysis of wastes associated with coffee production
Kovářová, Markéta ; Skoumalová, Petra (referee) ; Obruča, Stanislav (advisor)
This bachelor thesis is focused on study of potential production of extracellular hydrolytic enzymes by microorganisms – bacterium and moulds, which have been cultivated on spent coffee grounds. The theoretical part deals with characterization of coffee and utilization of coffee by-products. There are also subscribed microorganisms and enzymes which have been noticed. In experimental part coffee ground was used as the sole substrate for production of extracellular hydrolytic enzymes. Productions of protease, cellulase, mannase and lipase enzymes were observed. None-identified isolate of mould spontaneously contaminating spent coffee grounds was identified as the best producer of these enzymes. Subsequently the conditions of cultivation such as water content and shaking vs. static cultivation of this moulds were optimized. Further, we performed partial purification and pre-concentration of the enzyme cocktail by ultrafiltration, ultradialysis and PAGE-SDS characterization of extracellular enzymes was performed as well.
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